Benzene, mono-C10-13-alkyl derivs., distn. residues

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Remarks:

Earthworm reproduction study

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 20 - August 25, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): Appropriate amount of test substance was mixed into dry soil. Feed (cow manure) and water were then added.
- Controls: Negative control and positive control studies were also done.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: in-house
- Age at test initiation (mean and range, SD): 2-4 months

ACCLIMATION
- Acclimation period: 16 days
- Acclimation conditions (same as test or not): Yes, except that during acclimation the earthworms were kept in peat moss

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

20-22 degrees C

pH:

7.44-7.59

Moisture:

33.1-36.8%

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1L glass beakers covered with perforated plastic wrap secured with rubber bands.
- Amount of soil or substrate: 800 g
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): 70% sand, 20% kaolin clay, 10% sphagnum peat, and 1% calcium chloride
- Maximum water holding capacity (in % dry weigth): 34%

OTHER TEST CONDITIONS
- Photoperiod: 16 hrs light/8 hrs dark
- Light intensity: 489-616 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Day 0: body weights; Day 28: physical abnormalities and body weight; Day 57: number of juveniles

VEHICLE CONTROL PERFORMED: no

Nominal and measured concentrations:

Nominal: 0. 62.5, 125, 250, 500, and 1000 mg/kg dry soil

Reference substance (positive control):

yes

Remarks:

Carbendazim

Key result

Duration:

28 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

- Mortality at end of exposure period: There was no mortality of adults in the negative control or test groups.
- Total mass of adults at beginning of test: mean 300.0 +/- 14.97 g at Day 0
- Changes in body weight of live adults (% of initial weight) at end of exposure period: +0.17-0.21 g, there was no significant difference in weight gain between the negative control and test groups.
- No. of offspring produced: Control 141, 62.5 mg/L 153, 125 mg/L 148, 250 mg/L 139, 500 mg/L 158, and 1000 mg/L 147.
- Other biological observations: Adults showed no abnormalities in appearance or behaviour.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50 reproduction 0.8914 mg a.i./kg dry soil
- Other: NOEC 0.5 mg a.i./kg dry soil, LOEC 1 mg a.i./kg dry soil

Reported statistics and error estimates:

See table below.

Concentration (mg/kg dry soil)	Mortality (Percent)	Mean Change in Body Weight (g)	Mean Number of Juveniles
0	0	+0.21 +/- 0.040	141 +/- 19.5
62.5	0	+0.18 +/- 0.029	153 +/- 10.4
125	0	+0.17 +/- 0.038	148 +/- 31.6
250	0	+0.20 +/- 0.013	139 +/- 32.0
500	0	+0.21 +/- 0.013	158 +/- 11.6
1000	0	+0.19 +/- 0.022	147 +/- 16.1

Validity criteria fulfilled:

yes

Conclusions:

The EC50 of Benzene, mono-C10-13-alkyl derivs., distn. residues for earthworms is >1000 mg/kg dry soil (nominal) based on adult mortality. The NOECs for growth and reproductive effects (based on number of offspring produced) were 1000 mg/kg dry soil. (nominal).

Executive summary:

A study was performed to assess the toxicity of Benzene, mono-C10-13-alkyl derivs., distn. residues

to earthworms. Adult earthworms were exposed to concentrations of 0, 62.5, 125, 250, 500, and 1000 mg/kg dry soil of test substance for 28 days. The adults were then removed, and offspring were exposed for an additional 28 days. There were no behavioral or physical abnormalities noted. The EC50 for earthworms is >1000 mg/kg dry soil (nominal) based on adult mortality.  The NOECs for growth and reproductive effects (based on number of offspring produced) were 1000 mg/kg dry soil. (nominal).

Description of key information

The EC50 of Benzene, mono-C10-13-alkyl derivs., distn. residues for earthworms is >1000 mg/kg dry soil (nominal) based on adult mortality.  The NOECs for growth and reproductive effects (based on number of offspring produced) were 1000 mg/kg dry soil. (nominal).

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw

Long-term EC10, LC10 or NOEC for soil macroorganisms:

1 000 mg/kg soil dw